Outboard motor unit construction



Nov. 29, 1949 I (5. E. BUSKE 2,489,478

OUTBOARD MOTOR UNIT CONSTRUCTION Filed Jan. 11, 1947 2 Sheets-Sheet l Nov. 29, 1949 G. E. BUSKE OUTBOARi) MOTOR UNIT CONS'JPRL ICTION 2 Sheets-Sheet 2 Filed Jan. 11, 1947 II II lllll INVENTOR. gilberflfiufike Patented Nov. 29, 1949 OUTBOA RDTMOTOR UNIT CQNSTRUCTION Gilbert 1*]. Buske, Anson Township, Chippewa County, Wis, assignor to National Pressure Cooker Company, Eau. Claire, Wis, a corporation of Wisconsin Application January 11, 1947., Serial No. 721,595

9 Claims.

This invention relates to outboard motor units, and has to do more particularly with the motor In outboard motor units ofknown type, it is the usual practice to mount the power head, in-- cluding the motor and associated parts, on amounting plate at the'upper end of a motor support tube mounted for turning movement in a bearing member orsleeve having associated therewith a'clamp bracket structure for-securing the unit to the transom or sill of a boat. It is desirable that the submerged portion of the motorsupport tube assembly, when the unit is in use, be so formed as to present minimum resistance to passage thereof through the water. To that end, in certain known outboard motor units the motor support tube properis rather short and has secured'to its lower end a housing of proper form to present'low resistance to its passage through the water, there being secured to, the lower end of this housingagear case which carries the propeller shaft, with the propeller thereon, suitable gearing for driving the, propeller shaft and a pump for supplying cooling water to the motor or engine. The motor support tube, together with the housing and the-gear case,-constitute the motor support tube assembly. In the known units referred to, the housing and the'gear case are secured together .andto the motor support tube by screw studs of considerable length passing through a fitting secured on the lower end of the tube and through the housing into the gear case, the studs having threaded engagement with the gear case. The housing and the gear case thus provide, in effect, a column of substantial length anchored at its lower end to the long screw studs and at its upper'end 'to'the lower end of the motor support tube. The use of long studs adds substan'tia'lly to the weight of the structure as a whole, sin-'ce thestuds should' be .form'ed of steel or like metal having a-deouate strength to withstand the tension and vibration to which they are subjected i-n.' use.' In addition, the use of-the long studs referred to results in objectionable loss ofitime in assembling the parts, since the studs must be inserted with-care and accuracy through the various parts-and secured thereto. In view ofthe fact that outboard motor units are fre quen-tly used for propelling boats in shallow water through heavy growth of grasses and weeds, it is of importance that thesubmerged portion of the unit be free. of projecting studs, nuts, or like elements, such as would-be apt to catch grass, weeds, or other growth-through which" the :boat is protube supportassembly of such a unit.

, pelled.

My invention is directed to the :provision of an outboardmotor unitiwhich avoids the objections to the .known units above referred to. To that end, I provide .amotor support tube assembly of comparatively lighti weight c'omprising a housing secured to the lower end of the motor support tube and a gear case seating on and secured to the lower end of the housing, the means for securing the gear case to the housing being disposed within the latter and the gear case, so as to avoid objectionable projections at the under water area of the assembly. By securing the gear case to the lower end of the housing, comparatively short securing screws of light weight may be utilized, thereby effecting a substantial saving in weight of the assembly and, since the gear case is secured to the lower end of the housing which is fixed at its upper end'to the lower end of the motor support tube, providing a rigid structure of adequate mechanical strength and which is not subject to objectionable vibration. More specincally, the means for securing the gear case to the bottom of the housing comprises a first securing screw which may bei-fixed to the housing, onto which the gear case may be threaded so as to seat against the bottom of the housing, and a second securing screw cooperating with the housing and the gear case for securing them together, this second screw having an abutment member disposed within an outwardly opening recess in the gear case, so as to be accessible from the exterior thereof for detaching the second screw and permitting of the gear case being unthreaded from the first securing screw, so as to be removed from the housing when desired. That renders it possible to remove and replace the gear case as a unit with expedition and facility, as conditions may require. That is advantageous, since, in general, the gear case is the only part of the assembly which may require to 'be removed for replacement, repair or cleaning of-parts. The securing screw onto which the gear case is threaded has associated therewith means cooperating with means on the gearca-se for accurately positioning the latter on the housing, and the other screw for securing the gear case to the housing conveniently is disposed adjacent thev rear or stern of the gear .case with its abutment member disposed.v

in a recess of the gear. case.v opening rearward thereof, this reces being adapted for reception of 1318 pump unit removably mounted therein andproviding a closurefor the recess. Further.

obfects and advantages of my invention will appear from the detail description.

In the drawings:

Figure 1 is a side view 01 an outboard motor unit embodying my invention, the bearing sleeve for the motor support .tube being in part broken away and shown in section;

Figure 2 is a perspective stern view, on an enlarged scale, of the gear case and the parts carried thereby of themotor support tube assembly of my invention, the propeller being omitted for clearness of illustration:

Figures 3 and 3A, taken together, constitute a view, on an enlarged scale, partly in vertical section and partly in elevation, of the motor support tube assembly.

Figure 4 is a fragmentary, sectional view taken substantially on line 4-4 of Figure 3A; and

Figure 5 is a plan view of the gear case, taken substantially on line 55 of Figure 3A.

I have illustrated my invention, by way of example, as embodied in an outboard motor unit comprising a power head 1, which includes the engine or motor and its appurtenances, mounted on a suitably formed mounting plate 8 secured, in a manner to be explained more fully presently, on the upper end of a motor support tube 9 mounted for turning movement in a lengthwise split sleeve l carrying a clamp bracket II by means of which the unit may be secured to the transom or sill of a boat in a known manner. A housing I2 is secured to the lower end of tube 9 and a gear case 3- seats at its upper end on the lower end or bottomof housing |2, to which it is secured. The mounting plate 8, tube 9, housing l2 and gear case |3, together constitute the motor support tube assembly with which my invention is concerned.

The upper end portion of motor support tube 9 is knurled exteriorly at M. The mounting plate 8 is formed as a casting of aluminum or other light weight alloy, and has an integral depending neck I5 which is cast about the knurled area I4 of tube 9 and thereby directly secured to this tube. The lower portion I! of tube 9 is also knurled exteriorlv and has cast thereabout the upper end portion of housing l2. which also is in the form of an aluminum or other light wei ht alloy casting. The mounting plate 8 and the motor support tube 9 and the housing I2 are thus secur d together without the use of screw studs or other members of like character and provide a unitary structure of light weight and ade uate mechanical strength.

The housin I2 flares downward, as shown in Figures 3 and 3A, and is of substantially fiatten d ellipti al shape in cross section for the ma or portion of its len th, merging into the more or less rounded upper portion which receives and is secured on t e low r end portion of tube 9. At its r ar, or stern, the hou ing I2 is form d to provide a downwardly inclined and r arwardlv opening discharge nozzle I8, through whi h cooling water and exhaust ases are dischar d. such wat r and gases passing to housin I2 through tube 9 in a manner well known in t e art.

Housing I2 is provided, .at the bottom thereof, with a transverse bottom wall 20 extendin forward a substantial distance from the downwardly and rearwardly inclined bottom Wall I9 of the discharge no zle l8. Wall 20 is provided, at the front thereof, with an upwardly extending boss 2| and housing I2 is further provided, at the front of its bottom, with an interior relatively thick boss 22. The lower faces of wall 20 and of boss 22 are disposed in a common plane with the lower edges of the side walls of housing I2, and provide therewith a fiat or planar seating surface for reception of a corresponding fiat or planar seating surface at the upper end of gear case |3, conforming to the seatin surface at thebottom of housing I2, that is, the surface extending forwardly from the inclined bottom wall I9 01 the discharge nozzle I8. The gear case I3 is of substantially fiattened eliptical cross section at its upper portion and is of increased width or thickness at its lower portion to accommodate the propeller shaft and associated gearing, as will appear more fully presently, and is provided with a downwardly extending skeg 24.

Gear case I3 is provided with an interior boss 25 extending from its upper end, in which seats an oil seal 26 of known type disposed about a drive shaft 21 having driving connection at its upper end to the motor and extending downward through the motor support tube assembly, as is known. The lower portion of shaft 21 extends through a bearing bushing 28 mounted in hub 25. A bevel gear 29 is splined on the lower end of shaft 2! and meshes with a bevel gear 30 fixed on the inner or forward end of propeller shaft 3|. Gear 39 is mounted in a bushing 32 suitably mounted in gear case I3, and propeller shaft 3| extends from gear 30 through a bearing bushing 33 carried by a tubular boss 34 of amounting plate 35 disposed in a recess 36 in the rear or stem portion of gear case 3. Recess 36 opens into a recess 31 of substantially greater height than recess 36, this recess 31 receiving a pump unit 38 removably secured therein by counter sunk screws 39 passing through unit 38 and plate 35 and threading into gear case |3. The pump unit 38 is of known type and comprises a suitable rotor or impeller 40 operated by an eccentric 4| fixed to propeller shaft 3|. charge of the pump unit 38 is connected by a passage 42, port 43, passage 44 and passage to a bore 43 extending from the upper end of boss- 25 at the rearward or stern portion thereof. The

passage 42 is formed in the pumpunit 38 and isv closed at its upper end by a cap 48, the port 43 also is formed in the pump unit 38 and the passages 44 and 45 and bore 46 are formed in the boss 25 of gear case |3, as will be clear from Figure 3A. Suitable gaskets and seals may be provided where required, as will be clear. supply tube 50 fits snugly at its lower end portion in bore 46 and extends upward through the assembly to the motor or engine for supplying water thereto from the pump unit 38, as is known. A propeller 5| (Figure 1), of suitable type, is secured on the propeller shaft 3| in a suitable manner, and when the motor or engine is in operation is driven therefrom by means of the shaft 2'! and associated gearing in the gear case |3, in an obvious manner, and cooling water is then supplied by the pump '38 through tube 50 to the engine.

The boss 22 receives a securing cap screw 52 inserted therethrough and extending downward within the forward portion of gear case |3. The latter is provided with a web element 53 extend-; ing transversely thereof and forwardly from boss 25, this web element being provided with an upwardly extending interiorly threaded boss 54. Head 55 of cap screw 52 seats on a washer 55 which seats on the upper face of-boss 22. An annular positioning member 51, conveniently in the form of a washer, fits snugly in a corresponding recess 58 in the under face of boss 22. The member 51 is of substantial thickness, is concentric with screw 52 and projects downward a substantial distance below the lower end or bottom of housing l2. The gear case I3 is provided, at the top of each side and adjacent the front thereof, with an'in'terior thickened-element or The dlS-' A water boss 60 provided in its upper face with an arcuate recess 6| disposed to receive snugl the positioning member or washer 51 as the gear case I3 approaches its position seating upon the lower end of' housing I2, as will appear more fully presently.

- Gear case I3 is provided at the stem or rear thereof with a thickened web element 63 extending from boss 25. This web element 63 is suitably bored for reception of a second securing cap screw 65 inserted therethrough, with its head 65 disposed at the under face of Web 63 with an intervening lock washer 66 of known type. The screw 65 threads into boss 2| of housing I2 and, in cooperation therewith and with web 63, provides additional means for securing gear case I3 to housin I2. It will be noted that the recess 31 is of adequate height to accommodate the head 65 of screw 64, and that the pump unit 38 provides an effective closure for recess 31, so that screw 64 is disposed within gear case I3 and housing I2, so as to be effectively shielded thereby, while being readily accessible by removal of the pum unit, which may be accomplished by removal of the securing screws 39 for that unit. The securing screw 52 and the parts associated therewith are also disposed within the housing I2 and gear .case I3 so as to be shielded thereby while avoiding objectionable projections exteriorly of those members.

' Ihe boss 22 is suitably bored and tapped from one side of the housing I2 for reception of a socket headed set screw 66 of known type. In applying the gear case I3 to housing I2, after washer 56 has been placed about screw 52, the latter is inserted through boss 22 and is fixed therein by means of the set screw 66. The positioning member or washer 51 is then placed about screw 52 and the gear case I3 is then inserted over screw 52 and is turned so as to thread boss 54 onto the lower end of this screw. As the gear case I3 approaches seating position on the lower end of housing I2, the washer 'I enters recesses SI of the bosses 60, thus accurately positioning gear case I3 relative to housing I2 transversely thereof, it being understood that at this time the washer 51 is also seated in recess 58 of boss 22. The gear case I3 is threaded onto screw 52 until it seats t ghtly at its upper end against the under face or bottom of housing I2. When that occurs, the upper end of gear case l3 may not be in accurate register with the lower end or bottom of housing I2. By loosening the set screw 66, so as to release screw 52 for turning movement in boss 22, gear case I3 may readily be turned into position in which it is in accurate register with the bottom of the housing I2, being held seated tightly against the housing by the screw 52. When gear case [3 is thus accurately positioned, the second securing screw 64 may be inserted through the web element 63 and threaded tightly through boss 2I, thus securing the housing and the gear case tightly together at the rear or stem portion thereof, the pump unit 38 being, of course, removed temporarily for that purpose. After that has been done, the pump unit 38 is replaced and the set screw 66 is then turned in tight so as to again lock or fix the forward securing screw 52 in boss 22.

It will be seen that the motor support tube assembly comprising the mounting plate 8, tube 9, housing I2 and gear case I3, provides a rigid structure of comparatively light weight and adequate mechanical strength, which is not subject to objectionable vibrations and in which the gear case may be removed and replaced with expedition and facility and without disturbing other .parts of the assembly. It will be understood that changes in detail may be made without departing from the field and scope of my invention, and I intend to include all such variations, as fall within the scope'of the appended claims, in this aplication in which the preferred form only of my invention has been disclosed.

I claim:

1. In an outboard motor unit, a motor support tube assembly comprising a substantially vertical tube, a motor mounting plate fixed on the upper end of said tube, a unitary housing directly secured at its upper end on the lower end of said tube, said housing having at its lower end an opening for discharge of exhaust gases, a gear case seating on the lower end of said housing, and means detachably securing said gear case to said housing, said means being disposed within said gear case and housing and shielded thereby.

2. In an outboard motor unit, a motor support tube assembly comprising a substantially vertical tube, a motor mounting plate fixed on the upper end of said tube, a unitary housing directly secured at its upper end on-the lower end of said tube, said housing having at its lower end an opening for dischargeof exhaust gases, a gear case seating on the lower end of said housing, and securing members disposed within said gear case shielded thereby and in cooperation therewith and with said housing detachably securing said gear case to said housing.

3. In an outboard motor unit, a unitary housing adapted to be secured at its upper end to a motor support tube and having at its lower end an opening for discharge of exhaust gases, a gear case seating at its upper end on the lower end of said housing, a securing screw fixed to said housing with its upper portion disposed therein, said screw extending downward from said housing within said gear case in threaded engagement therewith, said gear case having an outwardly opening water pump receiving recess remote from said screw and removable closure means therefor, and a headed securing screw passing through a part of said gear case and threading into said housing with its head disposed in said recess accessible therethrough upon removal of said closure means.

4. In an outboard motor unit, a unitary housing adapted to be secured at its upper end to a motor support tube and having a planar seating surface at its lower end, said housing having at its lower end an opening for discharge of exhaust gases, a gear case having a planar seating surface at its upper end seating on the lower end of said housing, a securing screw passing through an interior element of said housing fixed thereto and extending downward within said gear case in threaded engagement therewith, and means comprising a second screw having an abutment member at its lower end passing through elements of said gear case and housing and in cooperation therewith securing them together, said second screw being disposed within said housing and gear case and the latter having an outwardly opening water pump receiving recess accommodating said abutment member and giving access thereto from the exterior of said gear case.

5. In an outboard motor unit, a unitary housing adapted to be secured at its upper end to a motor support tube and having a planar seating surface at its lower end, said housing having at its lower end an opening for discharge of exhaust gases, a gear case-having a planar seating surface at its upper end seating on the lower end of said housing, the latter. having an interior boss adjacent its lower end, a headed securing screw passing through said boss-with-its head at the upper face thereof, said'screw extending downward within said. gear case into threaded engagementtherewith, means operable exteriorly of said housing for optionally fixingsaid screw to said boss, said gear case having a web element therein remote from said screw and an outwardly opening water pump receivingrecess extending from the under face of said web element, and a second headed securing screw passing through said web element with its head at the under face thereof and threading into said housing.

6. In an outboard motor unit, a unitary housing adapted to be secured at its upper end to a motor support tube and having a planar seating surface at its lower end, said housing having at its lower end an opening for-discharge of exhaust gases, a gear case having a planar seating surface at its upper end seating onthe lower end of said housing, the latter having an interior boss adjacent its lower end, a headedsecuring screw passing through said boss with its head at the upper face thereof, said screw extending downward within said gear case into threaded engagement therewith, means operable exteriorly of said housing for optionally fixing said screw to said boss,

a positioning member extending downward from said boss concentric with said screw, said gear case having elements cooperating with said positioning member for accurately positioning said gear case relative to said housing as it approaches seating position thereon, and means comprising a second screw having anabutment member at its lower end passing through elements of said gear case and housing and in cooperation therewith securing them together, said second screw being disposed within said housing and gear case and the latter having an outwardly opening water pump receiving recess accommodating said abutment member and giving access thereto from the exterior of said gear case.

'7. In an outboard motor unit, a unitary housing adapted to be secured at its upper end to a motor support tube and having a planar seating surface at its lower end, said housing having at its lower end an opening for discharge of exhaust gases, a gear case having a planar seating surface at its upper end seating on the lower end of said housing, the latter having an interior boss adjacent its lower end, a headed securing screw passing through said boss with its head at the upper face thereof, said screw extending downward within said gear case into threaded engagement therewith, means operable exteriorly of said housing for optionally fixing said screw to said boss, the latter having in its under facean annular recess substantially concentric ,with said screw, an annular positioning memberv disposed about said screw adapted to seat snugly in saidrecess and to project downward from said boss below the seating surfaceof said housing, said gear case having recessed means disposed and adapted for reception of said positioning memher and cooperating therewith for accurately p0,

sitioning said gear case relative to said housing, said gear case having a webelement therein remote from said screw andan outwardly opening water pump receiving recess extending from the 8: under. face of said web element, anda secondheaded securing screw passing through said web element with its head at the under face thereof and threading into said housing.

8. In an outboard motor unit, a'unitary 110115? ing adapted to be secured at its upper endto a motor support tube and havinga planar seating surface at its lower end, said. housing having at its lower end an opening for discharge of exhaust gases, a gear case having a planar seating surface at its upper end seating on the lower end of said housing, the latter havin an interior boss adjacent the lower end of its forward portion, a headed securing screw passing through said boss with its head at the upper face thereof, said screw extending downward within the forward portion of said gear case into threaded engagement therewith, means operable exteriorly of said housing for optionally fixing said screw to said boss, said gear case having in its stern portion an outwardly opening recess and a web element overlying said recess, said housing having a securin element overlying said web element, a secondsecuring screw having an abutment memher at the underface of said web element, said second screw cooperatin with said securing element and web element for securing said gear case to said housing, and a removable pump unit mounted in said recess providing a closure therefor.

9. In an outboard motor unit, a unitary housing adapted to be secured at its upper end to a motor support tube and having a planar seating surface at its lower end, said housing having at its lower end an opening for discharge of exhaust gases, a gear case having a planar seating surface at its upper end seating on the lower end of said housing, the latter having an interior boss adjacent the lower end of its forward portion, a headed securing screw passing through said boss with its head at the upper face thereof, said screw extending downward within the forward portion of said gear case into threaded engagement therewith, means operable exteriorly of said housing for optionally fixing said screw to said boss, said gear case having in its stern portion an outwardly opening recess adapted to receive a removable pump unit and a web element overlying said recess, said housing having a securing element overlying said web element, and a second securing screw havin an abutmentmember at the underface'of said web element, said second screw cooperating with said securing element and web element for securing said gear case to-said housing.

GILBERT E. BUSKE.

REFERENCES CITED The following references are of record in the file'of this patent:

UNITED STATES PATENTS Number Name Date 1,893,661 Smith Jan. 10, 1933 2,021,309 Irgens Nov. 19, 1935 2,143,573- Palmer Jan. 10, 1939 2,212,939 Irgens Aug. 27, 1940 2,351,050 Karey June 13,1944

FOREIGN PATENTS Number Country Date,

296,226 Great Britain Aug. 30, 1928 

